Diabetic nephropathy is the leading cause of kidney failure in the U.S. Kidney failure occurs more often in diabetic African-Americans than in Caucasians with diabetes. The cause for this higher propensity to kidney failure in African-Americans is not known. Recently, certain types of antihypertensive medications have been shown to slow down the rate of development of kidney failure once damage has occurred, however, to date, no treatment can prevent the development of kidney failure once a certain degree of kidney is present. Very little is known about the early stages of the disease, when kidney damage could be reversible or about possible differences in kidney function between African-Americans and Caucasians with early diabetes that could explain the propensity to kidney disease in African-Americans. We postulate that there are differences in intraglomerular hemodynamics and the hormonal regulation of the glomerular circulation, at the renin-angiotensin and nitric oxide systems level, between African-Americans and Caucasians that underlie the susceptibility to kidney disease in the African-American population. We plan to compare glomerular function and glomerular permselectivity between African-Americans and Caucasians with early diabetes and to study the role the renin angiotensin and nitric oxide systems in the regulation of the glomerular circulation. This may lead to therapies that could be started very early on in diabetic patients targeted at preventing the development of kidney complications.